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Division of Occupational Safety and Health
Three construction workers were
killed when a 23-foot-high, 20-foot-wide,
40,000-pound concrete wall
panel fell to the ground. The wall
panel was one of many making up the
exterior wall of a box-type, tilt-up
structure, where walls are composed
of panels secured in place by roof and
floor structural connections. Tilt-up
structures are a very common type of
construction where panels are fabri-cated
on site in a horizontal mold
then tilted up to form vertical walls.
This structure, by design, should have
had three permanent connections to
secure the roof, wall and floor systems
together to complete the structural
integrity of the box:
• Roof joists welded to plates that were
embedded in the walls
• Grout inserted between wall panel
and footing
• Reinforced concrete poured into the
pour-back or leave-out strip to tie the
wall to the floor
Contractors at the Home Depot site were
largely unaware of tilt-up construction
requirements.
The 40,000-pound panel that fell and
killed three employees was not secured.
The wall panel was fabricated on site
horizontally and “tilted up” to vertical
on its footing. Temporary braces were
installed as specified. The construction
plan and OSHA regulations require
the following before braces can be
removed:
• Welders connect the wall panel to
the roof trusses with structural fillet welds
• The tilt-up contractor stabilizes the
wall panels by grouting at the base,
between the panels and the footing
• The tilt-up contractor completes the
structural connection from the wall
panels to the floor with concrete in
the pour-back/leave-out strip
Workers having lunch by the wall did not
know the 40,000-pound panel was free
standing.
Equipment problems, unfamiliarity with
requirements for tilt-up construction
and the contract documents, inadequate
training, and poor communication
between workers and contractors
contributed to this accident. The
general contractor was responsible for
bridging these procedural and
communication gaps.
The contract specified that 100 per-cent
of the welds were required to be
inspected. However, the inspector
only inspected a sample of the welding
and assumed welders had secured wall
panels to the roof steel with the
required structural welds. The inspector’s
report stated all welds were complete
and acceptable; in fact, several were
missing. The tilt-up contractor had not
secured the wall panels by grouting
nor completed the pour-back/leave-out
connection to the floor slab. The
wall panel was assumed to be secured
and stable when, in fact, it was not. It
was further assumed that it was safe to
remove the temporary braces from the
wall panel when, in fact, it was not.
Seven workers eating lunch in the
shade of the wall were not notified
that braces were about to be removed.
After brace removal, the wall panel,
lacking permanent connections, was
free standing, supported only by
alignment shims. When the panel
fell, two workers escaped, two were
grazed and slightly injured. Three
men were unable to escape the falling
panel and were killed instantly.
Accident investigators determined that
the accident, like most accidents,
resulted from a chain of events or factors.
If one of many people involved recog-nizes
an unsafe condition and does
something about it—or even voices a
warning or complaint—one link in
the chain is broken and the accident
“almost happens.” Often, few to none
of the people involved are aware of
the “close call.”
Tilt-up is a very popular construction
method, with over 14 million panels
installed in the United States.
Five contractors were cited for con-tributing
to this tragic accident,
because of:
Tilt-Up Wall Construction Can Be Deadly
Continued on page 2

Division of Occupational Safety and Health
Three construction workers were
killed when a 23-foot-high, 20-foot-wide,
40,000-pound concrete wall
panel fell to the ground. The wall
panel was one of many making up the
exterior wall of a box-type, tilt-up
structure, where walls are composed
of panels secured in place by roof and
floor structural connections. Tilt-up
structures are a very common type of
construction where panels are fabri-cated
on site in a horizontal mold
then tilted up to form vertical walls.
This structure, by design, should have
had three permanent connections to
secure the roof, wall and floor systems
together to complete the structural
integrity of the box:
• Roof joists welded to plates that were
embedded in the walls
• Grout inserted between wall panel
and footing
• Reinforced concrete poured into the
pour-back or leave-out strip to tie the
wall to the floor
Contractors at the Home Depot site were
largely unaware of tilt-up construction
requirements.
The 40,000-pound panel that fell and
killed three employees was not secured.
The wall panel was fabricated on site
horizontally and “tilted up” to vertical
on its footing. Temporary braces were
installed as specified. The construction
plan and OSHA regulations require
the following before braces can be
removed:
• Welders connect the wall panel to
the roof trusses with structural fillet welds
• The tilt-up contractor stabilizes the
wall panels by grouting at the base,
between the panels and the footing
• The tilt-up contractor completes the
structural connection from the wall
panels to the floor with concrete in
the pour-back/leave-out strip
Workers having lunch by the wall did not
know the 40,000-pound panel was free
standing.
Equipment problems, unfamiliarity with
requirements for tilt-up construction
and the contract documents, inadequate
training, and poor communication
between workers and contractors
contributed to this accident. The
general contractor was responsible for
bridging these procedural and
communication gaps.
The contract specified that 100 per-cent
of the welds were required to be
inspected. However, the inspector
only inspected a sample of the welding
and assumed welders had secured wall
panels to the roof steel with the
required structural welds. The inspector’s
report stated all welds were complete
and acceptable; in fact, several were
missing. The tilt-up contractor had not
secured the wall panels by grouting
nor completed the pour-back/leave-out
connection to the floor slab. The
wall panel was assumed to be secured
and stable when, in fact, it was not. It
was further assumed that it was safe to
remove the temporary braces from the
wall panel when, in fact, it was not.
Seven workers eating lunch in the
shade of the wall were not notified
that braces were about to be removed.
After brace removal, the wall panel,
lacking permanent connections, was
free standing, supported only by
alignment shims. When the panel
fell, two workers escaped, two were
grazed and slightly injured. Three
men were unable to escape the falling
panel and were killed instantly.
Accident investigators determined that
the accident, like most accidents,
resulted from a chain of events or factors.
If one of many people involved recog-nizes
an unsafe condition and does
something about it—or even voices a
warning or complaint—one link in
the chain is broken and the accident
“almost happens.” Often, few to none
of the people involved are aware of
the “close call.”
Tilt-up is a very popular construction
method, with over 14 million panels
installed in the United States.
Five contractors were cited for con-tributing
to this tragic accident,
because of:
Tilt-Up Wall Construction Can Be Deadly
Continued on page 2